I'm stumped with a pump

I have a small cast iron, gear pump that was working.

The gear is about an inch in diameter, .375 thick and the other gear (idler type) is a bit smaller.

No blockages, no clogs, all looks good. However, there are three set screws/plugs around the periphery of the pump equidistant at 120 degrees.

This thing no longer pumps but tries to do so.

There are no leaks. I did fiddle with the plugs as it was not doing well.

Help, anyone?

Thanks

j/b

Reply to
justme
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Are you spinning it in the right direction? The oil goes around the outside of the gears and the meshing gears pushes it out the outlet instead of letting the oil just go round and round and round...

Hidden check valve? STUCK hidden check valve?

Liquid too thin? Water and light fractions like gasoline are not meant for gear pumps.

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Reply to
Bruce L. Bergman

I've played with stuff like that, describes a fuel pump I messed with to a T. Had three spigots, an inlet and two outlets. The stinker was that it had a hidden over-pressure/check valve. Was hollow steel with a rubber tip. The rubber tip was the sealing part, when it got hard, crumbled and vanished, all semblance of pumping ceased, the outlet was now directly connected to the tank and the inlet. Unfortunately, the whole valve unit was crimped together, had to get a refurb, no separate parts available. Hope you have better(and cheaper) luck.

Stan

Reply to
stans4

Bruce,

It is the right direction. No hidden valves that I can see. Pump same liquid it has always pumped.

j/b

Reply to
justme

Stan,

This only has two ports, one in, one out.

Thanks

j/b

I've played with stuff like that, describes a fuel pump I messed with to a T. Had three spigots, an inlet and two outlets. The stinker was that it had a hidden over-pressure/check valve. Was hollow steel with a rubber tip. The rubber tip was the sealing part, when it got hard, crumbled and vanished, all semblance of pumping ceased, the outlet was now directly connected to the tank and the inlet. Unfortunately, the whole valve unit was crimped together, had to get a refurb, no separate parts available. Hope you have better(and cheaper) luck.

Stan

Reply to
justme

I've fixed a worn out pump like this before by taking the center section of the pump, the one that the gears ride in, and sanding it a little thinner. I use 220 grit sandpaper on a FLAT surface rough side up. Sand a few swipes across the paper, re-assemble and they usually pump again.

Shawn

Reply to
Shawn

Good idea, Shawn.

I have done that with vanes in a vacuum pump and it worked just fine. It didn't occur to me to do it with this pump. Will give it a try.

Thanks

j/b

Reply to
justme

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